1. Field of the Invention
This invention relates to the prevention of the unauthorized dubbing or pirating of a recorded signal.
2. Description of the Prior Art
As is disclosed in U.S. Pat. Nos. 4,163,253 and 4,100,575, it is known to protect against the unauthorized recording and reproducing of transmitted video signals. However, the conventional technology provided for such an anti-piracy system is not sufficiently reliable.